A panel of five serum microRNAs has been identified as a potential biomarker to diagnose early stage non-small cell lung cancer (NSCLC), according to a study published in EBioMedicine (2015; doi:10.1016/j.ebiom.2015.07.034).

Early stage NSCLC is asymptomatic and currently lacks a blood test to detect it. MicroRNAs (miRNAs) are a family of small, single-stranded noncoding RNAs that are critical regulators of numerous diseases, and their expression patterns have the potential to diagnose various types of cancer.

Previous studies have demonstrated that human body fluids, such as serum, contain numerous stable miRNAs, which are promising novel biomarkers for cancer detection including NSCLC. However, data on ethnically diverse cases of NSCLC are currently lacking. Developing biomarkers that are sensitive and reliable remains a major challenge for researchers.

This study, led by the group of Chen-Yu Zhang, MD, PhD, and Chunni Zhang, PhD, at Nanjing Advanced Institute for Life Sciences at Nanjing University in China, recruited 438 participants that included 221 patients with NSCLC, 161 control participants, and 56 patients with benign nodules. The participants were from both China and America.

High-throughput TaqMan Low-Density Array scanning was combined with an individual quantitative reverse transcription polymerase chain reaction (PCR) confirmation. This successfully identified a panel of five serum miRNAs including miR-483-5p, miR-193a-3p, miR-25, miR-214 and miR-7 that were significantly elevated in patients with NSCLC using samples from three independent Chinese cohorts.

Subsequently, a blind trial was then performed to assess the ability of the panel to diagnose NSCLC in an American cohort and to function as a reliable diagnostic indicator of NSCLC in patients of different ethnicities. The panel has a high accuracy to classified NSCLC cases and controls from both the Chinese and the American cohorts.

Most importantly, the panel correctly predicted stage I-II tumors and was capable of distinguishing NSCLC from benign nodules in the American cohort.

"This is the first multiethnic, multicentric, single-blind global analysis of miRNA expression patterns of NSCLC patients in four independent cohorts from five centers in both China and America," said corresponding author Chen-Yu Zhang, Director of Nanjing Advanced Institute for Life Sciences. “Thus this miRNA panel has potential utility as a common potential biomarker for detecting NSCLC in persons of different races.”

Zhang also described the blinded fashion of validating this multiethnic study, allowing it to achieve translational relevance. Further, he stated that the miRNA panel can differentiate malignant lesions from early stages of cancer even in the benign lesions that are frequently found by CT scans in high-risk populations. He explained that this will potentially lead to early interventions, therapy, and treatment options.